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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ANDROID_GUI_IGRAPHICBUFFERPRODUCER_H
     18 #define ANDROID_GUI_IGRAPHICBUFFERPRODUCER_H
     19 
     20 #include <stdint.h>
     21 #include <sys/types.h>
     22 
     23 #include <utils/Errors.h>
     24 #include <utils/RefBase.h>
     25 
     26 #include <binder/IInterface.h>
     27 
     28 #include <ui/Fence.h>
     29 #include <ui/GraphicBuffer.h>
     30 #include <ui/Rect.h>
     31 
     32 namespace android {
     33 // ----------------------------------------------------------------------------
     34 
     35 class Surface;
     36 
     37 /*
     38  * This class defines the Binder IPC interface for the producer side of
     39  * a queue of graphics buffers.  It's used to send graphics data from one
     40  * component to another.  For example, a class that decodes video for
     41  * playback might use this to provide frames.  This is typically done
     42  * indirectly, through Surface.
     43  *
     44  * The underlying mechanism is a BufferQueue, which implements
     45  * BnGraphicBufferProducer.  In normal operation, the producer calls
     46  * dequeueBuffer() to get an empty buffer, fills it with data, then
     47  * calls queueBuffer() to make it available to the consumer.
     48  *
     49  * This class was previously called ISurfaceTexture.
     50  */
     51 class IGraphicBufferProducer : public IInterface
     52 {
     53 public:
     54     DECLARE_META_INTERFACE(GraphicBufferProducer);
     55 
     56     enum {
     57         BUFFER_NEEDS_REALLOCATION = 0x1,
     58         RELEASE_ALL_BUFFERS       = 0x2,
     59     };
     60 
     61     // requestBuffer requests a new buffer for the given index. The server (i.e.
     62     // the IGraphicBufferProducer implementation) assigns the newly created
     63     // buffer to the given slot index, and the client is expected to mirror the
     64     // slot->buffer mapping so that it's not necessary to transfer a
     65     // GraphicBuffer for every dequeue operation.
     66     virtual status_t requestBuffer(int slot, sp<GraphicBuffer>* buf) = 0;
     67 
     68     // setBufferCount sets the number of buffer slots available. Calling this
     69     // will also cause all buffer slots to be emptied. The caller should empty
     70     // its mirrored copy of the buffer slots when calling this method.
     71     virtual status_t setBufferCount(int bufferCount) = 0;
     72 
     73     // dequeueBuffer requests a new buffer slot for the client to use. Ownership
     74     // of the slot is transfered to the client, meaning that the server will not
     75     // use the contents of the buffer associated with that slot. The slot index
     76     // returned may or may not contain a buffer. If the slot is empty the client
     77     // should call requestBuffer to assign a new buffer to that slot. The client
     78     // is expected to either call cancelBuffer on the dequeued slot or to fill
     79     // in the contents of its associated buffer contents and call queueBuffer.
     80     // If dequeueBuffer return BUFFER_NEEDS_REALLOCATION, the client is
     81     // expected to call requestBuffer immediately.
     82     //
     83     // The fence parameter will be updated to hold the fence associated with
     84     // the buffer. The contents of the buffer must not be overwritten until the
     85     // fence signals. If the fence is NULL, the buffer may be written
     86     // immediately.
     87     virtual status_t dequeueBuffer(int *slot, sp<Fence>* fence,
     88             uint32_t w, uint32_t h, uint32_t format, uint32_t usage) = 0;
     89 
     90     // queueBuffer indicates that the client has finished filling in the
     91     // contents of the buffer associated with slot and transfers ownership of
     92     // that slot back to the server. It is not valid to call queueBuffer on a
     93     // slot that is not owned by the client or one for which a buffer associated
     94     // via requestBuffer. In addition, a timestamp must be provided by the
     95     // client for this buffer. The timestamp is measured in nanoseconds, and
     96     // must be monotonically increasing. Its other properties (zero point, etc)
     97     // are client-dependent, and should be documented by the client.
     98     //
     99     // outWidth, outHeight and outTransform are filled with the default width
    100     // and height of the window and current transform applied to buffers,
    101     // respectively.
    102 
    103     struct QueueBufferInput : public Flattenable {
    104         inline QueueBufferInput(const Parcel& parcel);
    105         inline QueueBufferInput(int64_t timestamp,
    106                 const Rect& crop, int scalingMode, uint32_t transform,
    107                 sp<Fence> fence)
    108         : timestamp(timestamp), crop(crop), scalingMode(scalingMode),
    109           transform(transform), fence(fence) { }
    110         inline void deflate(int64_t* outTimestamp, Rect* outCrop,
    111                 int* outScalingMode, uint32_t* outTransform,
    112                 sp<Fence>* outFence) const {
    113             *outTimestamp = timestamp;
    114             *outCrop = crop;
    115             *outScalingMode = scalingMode;
    116             *outTransform = transform;
    117             *outFence = fence;
    118         }
    119 
    120         // Flattenable interface
    121         virtual size_t getFlattenedSize() const;
    122         virtual size_t getFdCount() const;
    123         virtual status_t flatten(void* buffer, size_t size,
    124                 int fds[], size_t count) const;
    125         virtual status_t unflatten(void const* buffer, size_t size,
    126                 int fds[], size_t count);
    127 
    128     private:
    129         int64_t timestamp;
    130         Rect crop;
    131         int scalingMode;
    132         uint32_t transform;
    133         sp<Fence> fence;
    134     };
    135 
    136     // QueueBufferOutput must be a POD structure
    137     struct QueueBufferOutput {
    138         inline QueueBufferOutput() { }
    139         inline void deflate(uint32_t* outWidth,
    140                 uint32_t* outHeight,
    141                 uint32_t* outTransformHint,
    142                 uint32_t* outNumPendingBuffers) const {
    143             *outWidth = width;
    144             *outHeight = height;
    145             *outTransformHint = transformHint;
    146             *outNumPendingBuffers = numPendingBuffers;
    147         }
    148         inline void inflate(uint32_t inWidth, uint32_t inHeight,
    149                 uint32_t inTransformHint, uint32_t inNumPendingBuffers) {
    150             width = inWidth;
    151             height = inHeight;
    152             transformHint = inTransformHint;
    153             numPendingBuffers = inNumPendingBuffers;
    154         }
    155     private:
    156         uint32_t width;
    157         uint32_t height;
    158         uint32_t transformHint;
    159         uint32_t numPendingBuffers;
    160     };
    161 
    162     virtual status_t queueBuffer(int slot,
    163             const QueueBufferInput& input, QueueBufferOutput* output) = 0;
    164 
    165     // cancelBuffer indicates that the client does not wish to fill in the
    166     // buffer associated with slot and transfers ownership of the slot back to
    167     // the server.
    168     virtual void cancelBuffer(int slot, const sp<Fence>& fence) = 0;
    169 
    170     // query retrieves some information for this surface
    171     // 'what' tokens allowed are that of android_natives.h
    172     virtual int query(int what, int* value) = 0;
    173 
    174     // setSynchronousMode set whether dequeueBuffer is synchronous or
    175     // asynchronous. In synchronous mode, dequeueBuffer blocks until
    176     // a buffer is available, the currently bound buffer can be dequeued and
    177     // queued buffers will be retired in order.
    178     // The default mode is asynchronous.
    179     virtual status_t setSynchronousMode(bool enabled) = 0;
    180 
    181     // connect attempts to connect a client API to the IGraphicBufferProducer.
    182     // This must be called before any other IGraphicBufferProducer methods are
    183     // called except for getAllocator.
    184     //
    185     // This method will fail if the connect was previously called on the
    186     // IGraphicBufferProducer and no corresponding disconnect call was made.
    187     //
    188     // outWidth, outHeight and outTransform are filled with the default width
    189     // and height of the window and current transform applied to buffers,
    190     // respectively.
    191     virtual status_t connect(int api, QueueBufferOutput* output) = 0;
    192 
    193     // disconnect attempts to disconnect a client API from the
    194     // IGraphicBufferProducer.  Calling this method will cause any subsequent
    195     // calls to other IGraphicBufferProducer methods to fail except for
    196     // getAllocator and connect.  Successfully calling connect after this will
    197     // allow the other methods to succeed again.
    198     //
    199     // This method will fail if the the IGraphicBufferProducer is not currently
    200     // connected to the specified client API.
    201     virtual status_t disconnect(int api) = 0;
    202 };
    203 
    204 // ----------------------------------------------------------------------------
    205 
    206 class BnGraphicBufferProducer : public BnInterface<IGraphicBufferProducer>
    207 {
    208 public:
    209     virtual status_t    onTransact( uint32_t code,
    210                                     const Parcel& data,
    211                                     Parcel* reply,
    212                                     uint32_t flags = 0);
    213 };
    214 
    215 // ----------------------------------------------------------------------------
    216 }; // namespace android
    217 
    218 #endif // ANDROID_GUI_IGRAPHICBUFFERPRODUCER_H
    219